Stud for fire rated gypsum board wall

ABSTRACT

A fire rated gypsum board wall and a sheet metal stud forming a part of the wall. The stud has a continuous flange that lies on the exterior surface of one side of the wall. The flange totally covers and seals the joint between abutting gypsum panels so as to elimiate further fastening and/or taping of such joint. The stud is provided with strategically located excisions that reduce the cross-sectional area of the heat flow path through the stud and afford visual inspection openings which are useful during erection of the wall to achieve alignment of the studs and the wall boards.

United States Patent Tillisch et al.

STUD FOR FIRE RATED GYPSUM BOARD WALL Inventors: Paul W. Tillisch;George E. Meyer,

both of Antioch; Hans D. Christansen, Walnut Creek, all of Calif.

Kaiser Gypsum Company, inc, Oakland, Calif.

Filed: Dec. 13, 1972 Appl. No.: 314,594

Assignee:

U.S. Cl 52/738, 52/481, 52/495 Int. Cl. E04c 3/07 Field of Search52/479, 481, 483, 495,

References Cited UNITED STATES PATENTS 11/1929 Mays et al. 52/354 X11/1965 Downing 52/481 X 3,345,787 10/1967 Busscher 52/481 X 3,508,3684/1970 Tischuk et al. 52/726 X 3,702,044 11/1972 Balinski 52/495 X3,740,912 6/1973 Sauer et a1 52/495 X Primary Examiner-Price C. Faw, Jr.Attorney, Agent, or Firm-James E. Toomey [5 7] ABSTRACT A fire ratedgypsum board wall and a sheet metal stud forming a part of the wall. Thestud has a continuous flange that lies on the exterior surface of oneside of the wall. The flange totally covers and seals the joint betweenabutting gypsum panels so as to elimiate further fastening and/or tapingof such joint. The stud is provided with strategically located excisionsthat reduce the cross-sectional area of the heat flow path through thestud and afford visual inspection openings which are useful duringerection of the wall to achieve alignment of the studs and the wallboards.

6 Claims, 4 Drawing Figures STUD FOR FIRE RATED GYPSUM BOARD WALL Thisinvention relates to a fire rated gypsum board wall and particularly toa framing system and improved stud for such wall.

A preferred embodiment of the present invention qualifies for a 2-hourrating, as prescribed under ASTM design specification E1l9-69, and canbe utilized where building codes require such rating. For example, inbuildings having an elevator shaft, it is typical that the wallenclosing or defining the shaft be of a 2-hour rating.

Accordingly, it is an object of the present invention to provide animproved fire rated wall constructed with gypsum boards or panels.Achievement of this object is possible according to the presentinvention by provision of an improved sheet metal stud which is soconfigured as to minimize the amount of metal used and thereforeminimize the area of the path available for heat conduction through awall employing such stud.

A feature and advantage of reducing the amount of metal required toconstruct the stud is that the cost of the stud is reduced as well asthe weight of the stud and consequent exertion required by workmenconstructing such wall.

Another object of the present invention is to provide a wall having theadvantageous characteristics referred to above which can be constructedfrom only one side of the wall. Achievement of this object is extremelyimportant in enclosing elevator shafts since it eliminates the need forscaffolding within the elevator shaft and materially enhances the safetywith which the workmen installing the wall can work. According to thepresent invention, the joints on one side of the wall (the elevatorshaft side of the wall), are spanned by a continuous metallic flangewhich seals any possible air flow paths without necessitating access tosuch side for installation of fasteners and/or taping compound.

A factor contributing to achievement of the aforestated object is thatportions of a stud employed in the present invention are excised todefine inspection openings through which a workman can determine whetherthe relative position between the edge of a gypsum board and a stud iscorrect. Additionally, the material removed from the web of the stud todefine the inspection openings reduces the area of the stud throughwhich heat can be conducted.

The foregoing, together with other objects, features and advantages,will be more apparent after referring to the following specification andaccompanying drawing in which:

FIG. 1 is a fragmentary perspective view of a wall constructed accordingto the present invention with portions being broken away to revealinternal details;

FIG. 2 is a fragmentary perspective view of a. stud constructedaccording to the present invention;

FIG. 3 is a cross-sectional view of the wall. taken along the planedesignated by line 3-3 of FIG. 1; and,

FIG. 4 is a cross-sectional view of a known prior art stud.

Referring more particularly to the drawing, reference numeral 12generally indicates a stud according to the present invention which issupported at the upper and lower ends thereof by a J-shaped trackl3,-the lower track, only, being shown in the drawing. Tracks 13 ineludea web 14 from the opposite edges of which extend respectively arelatively wide flange I5 and a relatively narrow flange 16. The tracksare suitably anchored to the floor and ceiling surfaces in the buildingin which the wall according to the present invention is installed.Similar J-shaped tracks, one of which is indicated as 13' in FIG. 1 areprovided at opposite horizontal ends of a wall structure embodying thepresent invention. Spaced along web 14 of tracks 13 and 13 are tabs 17which can be bent out from the plane of the web during installation asdescribed hereinafter. The edge of tab 17 closest to flange 15 is spacedfrom such flange by a distance approximating the thickness of the gypsumboard that abuts flange l5. J-shaped track 13 can be 2S-gauge (0.021inch in thickness) galvanized sheet steel. One surface of the wall, forconvenience hereinafter referred to as the elevator shaft side or simplyshaft side of the wall, is defined by fire rated gypsum wall boards 18,18' which in one wall structure designed according to the invention are1-inch gypsum boards having a width of 2 feet and a length suitable forthe height of the wall. The opposite side of such exemplary wall,sometimes referred to hereinafter as the corridor side, is formed by twolayers of 5/8 inch gypsum boards 19 and 20. The outer or face boards 20meet at a butt joint 22 which is aligned with stud 12; such joint isfinished in accordance with conventional taping techniques not shown inthe drawing or further described hereinafter.

With specific reference to FIG. 2, stud 12 includes a continuous flange24 which is disposed on the shaft side of the wall and extends withoutinterruption the full height of the wall so that the margins of boards18, 18' adjacent the joint therebetween are fully covered by the flange.The flange has a width such that it retains gypsum boards 18, 18' inplace even in the presence of slight misalignment and such that thesurface of the flange makes face-to-face contact with the surface of theboards to substantially seal the joint against passage of air currentstherethrough. In one stud designed according to the present invention,galvanized steel, such as 24-gauge (0.027 inch in thickness) is employedand flange 24 has a width of l-% inch so that the flange overlaps thesurface margin of gypsum boards 18, 18' by about 13/16 inch. At one edge26 of flange 24, the material is bent to form a return bend portion 28which extends-along the reverse face of the flange. The opposite edge ofthe flange terminates in a rolled over por- .cated at40 in FIG.'2. Tab40 is bent outfrorn web segtion or hem 27. The return bend and rolledover portion stiffen the flange and define rounded edges which easeengagement of boards with the stud. Return bend portion 28 continues toa point medial of flange 24 at which there is a degree bend line 30 fromwhich extends a web section 32. As can be seen most clearly in FIG. 3,web section 32 is normal or perpendicular'to flange 24. Web section 32extends to a bend line 34, from which projects laterally a plate section36. As can be seen in FIG. 3, web section 32 has a width equivalent tothe thickness of gypsum board 18 so that there is defined, between thereverse side of flange 24 and plate section 36, a groove or slot 38 intowhich the edge of the gypsum board is snugly received.

Struck from web section 32 at spaced apart intervals therealong are aplurality of tabs, one of which is indimerit 32 along bend line 34sothat is confronts the reverse side of flange 24 to define adiscontinuous groove 42 which snugly receives the edge of wall board 18.To facilitate insertion of wall board 18 into groove 42, the edge of tab40 remote from bend line 34 is flared or curved away from groove 42, asat 44. Tab 40 is strengthened or reinforced by raising therefrom, by asuitable die or the like, one or more stiffeners 46 which stiffen thetab by defining a portion of material oblique of the plane of the tab.It will be noted that the bending out of tab 40 from web section 32defines an opening 48 in the web section; opening 48 has severaladvantageous characteristics which will be described in more detailhereinbelow. Although tabs 40 can be struck from plate section 36, theconstruction shown in FIG. 2 is considered at present the best mode ofcarrying out the invention.

Plate section 36 terminates in a bend line 50 from which extends,parallel to web section 32, a web section 52. The extent of web section52 depends on the desired thickness dimension of the hollow core of thewall, and particularly depends on the size of pipes and- /or conduits,if any, to be installed in the core of the partition. Web section 52extends to an edge 54 at which there is a flange 56 which affords anelement for receiving screws 58, or the like, for effecting attachmentof gypsum boards 19 and 20 to the stud.

At the edge of flange 56, opposite edge 54, there is a lip 60 whichstiffens the flange. As can be seen in FIG. 3, lip 60 is of limitedextent so that it is substantially spaced apart from web sections 32 and36 and tabs 40. In one stud configuration designed according to thepresent invention, web section 52 is about l- /2 inches wide and lip 60is ,4 inch wide, thereby providing a space of about 1 inch from the lipto web section 32. This space is sufficient to avoid significant heattransfer therethrough. Where even greater fire resistance is required(e.g., more than a 2-hour rating), it is anticipated that a l-inchgypsum board might be positioned in this space.

The operation and advantages of the present invention can be understoodby considering installation of a wall employing the invention. J-shapedtracks 13 are installed at the vertical and horizontal boundaries of thewall, and are fastened to existing structure. The relatively long flange15 of J-shaped track 13 is installed opposite from the side of the wallto which workmen have unrestricted access. In other words, when the wallis installed to define an elevator shaft, flange 15 is disposed on theshaft side. A gypsum board 18, which is typically 2 feet in width, iscut to a length less than the distance between the edges of confrontingflanges l6 and more than the distance between the edges of confrontingflanges 15. Typically, a length approximately 1 inch less than thevertical distance between confronting tracks 13 is appropriate. Gypsumboard 18 is slid laterally against end track 13 and is there held inplace, as shown in FIG. 1, by bending tabs 17 into place. The provisionof the tabs 17 eliminates the need for screws to hold the boards againstthe flange 15. Next, a'stud 12 is installed between the flanges oftracks 14 and is slid laterally until the edge of gypsum board 18 entersslot 38. Because of the presence of opening 48 adjacent tab 40, theworkmen can see through the opening and visually inspect the position ofthe edge to ascertain that the stud is fully engaged with the edge ofthe board. Secure engagement of the stud with the board is important toassure that theboard cannot be accidentally dislodged and to assurevertical alignment of the studs. Vertical alignment is particularlyimportant because the flange 56 must align with the edges of the boards20 for purposes of receiving the screws 58. The next gypsum board 18' isthen placed between tracks 13 and slid laterally so that it enters thediscontinuous groove 42 defined between respective tabs and flange 24.Because groove 42 is discontinuous, i.e., because tabs 40 are oflimitedextent, the relative position between the surface of web section 32 andthe edge of the board is visible at all times so that workmen canascertain when the board is snugly in place against web section 32.Another stud is installed until the edge of the preceding gypsum boardis fully engaged in slot 38 of the stud, and such procedure continuesuntil the opposite end of the wall is reached, whereupon tabs 17 arebent into place to retain the final gypsum board in place.

The opposite wall surface is completed in a conventional manner, firstby installing a plurality of gypsum boards 19, preferably oriented withtheir long dimension in a horizontal direction and fastened to flange 56by means of screws 58, and then by installation of surface panels 20followed by application of tape and compound to the joints 22 betweenadjacent panels 20.

Certain advantageous features can be perceived by reference to FIG. 3 ifit is assumed that the shaft side of the wall, i.e., the side at whichflange 24 is located,-

has reached an elevated temperature because of the presence of a fire inthe shaft. The sole heat conducting path from the shaft side of the wallis through web 32, a single layer of sheet steel. The cross-sectionalarea of this path is reduced to the extent that openings 48 are providedin web section 32. The heat path continues through web section 52,which, because it is typically provided with a series of openings 58 forwiring and/or piping, further reduces the cross-sectional area of theheat path. The length of the path is such that a 2-hour rating isachieved whereby the occupants on the corridor side of the wall haveadequate time to vacate the premises without injury. Another advantageafforded by openings 48 and 58 is that they act as thermal expansionjoints or sections whereby the tendency for the stud to twist inresponse to differential heating thereof is materially reduced. Thus,the stud construction, according to the present invention, if it twistsat all, does not twist sufficiently to permit gypsum boards 18, 18' toescape from grooves 38 and 42 or to permit the screws 58 in the boards19 and 20 from pulling free.

The continuous flange 24 secures the boards on the shaft side againstbeing displaced into the shaft should a worker fall against the insideof a board. Thus, the

'flange adds greatly to the safety of workers installing the wallsystem. The provision for visual inspection of the edges of boardsreceived behind the flange 24 provides means whereby the workers mayascertain if the boards are fully seated behind the flange and, thus,also contributes to the safety of the workers.

In one stud designed according to the present invention, tabs 40 andopenings 48 have a longitudinal extent of about 3 inches and are spacedon 12-inch centers throughout the length of the stud. Accordingly, thecross-sectional area of the heat path afforded by web section 32- isreduced by25 percent, thereby minimizing the amount of heat conductedthrough the wall and minimizing the distortion of the studs due todifferential heating thereacross. Moreover, the number and spacing oftabs 46 in such exemplary configuration is sufficient to afford firmengagement of gypsum board 18' within groove 42. The utility holes 58 inthe web section 52 further reduce the thermal conductivity of the stud.

A better appreciation of the advantages of the present invention can behad by comparing the same with the known prior art shown in FIG. 4. Itwill be noted that the stud, there disclosed, has a double web section32a as well as double web sections 52a. Accordingly, the cross-sectionalarea of the heat conduction path afforded by the prior art device ismore than twice that afforded by the present invention. Because web sections 52a are doubled and are spaced from one another. it is at bestdifficult and at worst impossible to provide openings through them forutility lines or for reducing the cross-sectional area of the heatconduction path through the wall of which the prior art stud is a part.Moreover, the resiliency in the sheet metal of which the stud is madehas in some cases made the manufacturer spot weld the web sectionstogether, as at W, so as to avoid separation of gypsum boards whenexposed to fire. Finally, the disclosed prior art stud employs aconsiderably greater amount of sheet metal than is required in the studof the present invention, thereby increasing the cost and the weightthereof.

Another example of the prior art is found in [1.5. Pat. No. 3,217,460.This patent is in the field of non-fire rated walls and discloses asheet metal stud wherein the channeled edge of the stud does not have acontinuous flange totally covering and sealing the joint betweenadjacent gypsum panels. The resultant wall requires taping or groutingif the joint is to be sealed and offers little resistance todisplacement by internal force applied to the panel received in thechannel with the discontinuous flange.

Thus, it will be seen that the present invention provides a gypsum boardwall that can be rapidly installed,

- and that affords a two-hour fire rating. Additionally,

the wall is so arranged that it can be fabricated from only one sidethereof thereby rendering the wall construction suitable for enclosingelevator shafts and the like.

Although one embodiment-of the invention has been shown and described,it will be obvious that other adaptations and modifications can be madewithout departing from the true spirit and scope of the invention.

What is claimed is:

1. A stud for supporting a gypsum board, hollow core wall that is firerated for flame exposure from at least one side thereof, the wall beingof the type that has a plurality of coplanar first gypsum boards of afirst thickness dimension on said one side and a plurality of coplanarsecond gypsum boards on the side opposite said one side, said studenabling said wall to be assembled from the side opposite said one sidewithout the need for anyone on said one side, and comprising in aunitary integral sheet metal structure: a continuous flange, adapted tocover the joint between abutting board edges on said one side of saidwall so as to lie in substantial contact with the outer surface of themargin of the boards adjacent the abutting edges thereof, said flangebeing defined by an outer planar element extending from one edge of theflange to the other and an inner planar element folded upon and beneaththe outer planar element from said other edge to a medial region of theflange; a first web section extending normal from the inner planarelement at the medial region of said flange to a first bend linedisposed at a distance from said flange corresponding to the thicknessof the boards on said one side of the wall; a plate section extendingfrom said first bend line in parallelism to said flange and beneath theouter planar element thereof on the side opposite that beneath whichsaid inner planar element extends to define, in cooperation with theouter planar element, a substantially continuous groove for receivingand retaining the edge of one of said boards of said one side of thewall, said plate section being disposed to reside on the side of saidboards opposite said one side; a plurality of spaced apart tabs struckfrom one of said sections so as to be coplanar with said plate sectionand extend from said first bend line in a direction opposite said platesection to define, in cooperation with the inner planar element of theflange, a discontinuous groove for receiving the edge of the other ofsaid boards of said one side of the wall; a

second bend line parallely spaced from said first bend line at the endof the plate section opposite the first bend line; a second web sectionextending from said second bend line perpendicular to the plate section,said second web section terminating at an edge disposed at a distancefrom said plate corresponding to the thickness of the hollow core; and asecond flange extending from last said edge in parallelism with saidcontinuous flange for affording attachment of the boards that define thesecond side of the wall, the combination of said second flange, saidsecond web and said plate section defining a channel section spaced fromsaid one side, said channel section reinforcing said stud againstdistortion in the presence of an elevated temperature on said one side.

2. A stud according to claim 1 wherein said first web section defines atleast one opening therein for affording visual access to saidsubstantially continuous groove from the side of said first sectionopposite said groove.

3. A stud according to claim 1 wherein said tabs are struck from saidfirst web section thereby defining a plurality of spaced apart openingsin said first web section to afford visual access to said substantiallycontinuous groove from the side of said first section opposite saidgroove.

4. A stud according to claim 1 including a lip extending from a portionof said second flange remote from said edge, said lip extendinggenerally normal to said second flange toward said first mentionedflange for reinforcin'g said second flange, said lip terminating inspaced apart relation to said first mentioned flange.

5. A stud according to claim 3 wherein said tabs include at the marginthereof remote from said second bend line a flared portion that iscurved away from said flange for facilitating entry of the edge of agypsum board into said discontinuous groove.

6. A stud according to claim 1 wherein said tabs each include at leastone reinforcing rib extending generally normal to said first bend line,said rib being formed integrally of said tab andincluding a portionoblique of the plane of said tab.

1. A stud for supporting a gypsum board, hollow core wall that is firerated for flame exposure from at least one side thereof, the wall beingof the type that has a plurality of coplanar first gypsum boards of afirst thickness dimension on said one side and a plurality of coplanarsecond gypsum boards on the side opposite said one side, said studenabling said wall to be assembled from the side opposite said one sidewithout the need for anyone on said one side, and comprising in aunitary integral sheet metal structure: a continuous flange, adapted tocover the joint between abutting board edges on said one side of saidwall so as to lie in substantial contact with the outer surface of themargin of the boards adjacent the abutting edges thereof, said flangebeing defined by an outer planar element extending from one edge of theflange to the other and an inner planar element folded upon and beneaththe outer planar element from said other edge to a medial region of theflange; a first web section extending normal from the inner planarelement at the medial region of said flange to a first bend linedisposed at a distance from said flange corresponding to the thicknessof the boards on said one side of the wall; a plate section extendingfrom said first bend line in parallelism to said flange and beneath theouter planar element thereof on the side opposite that beneath whichsaid inner planar element extends to define, in cooperation with theouter planar element, a substantially continuous groove for receivingand retaining the edge of one of said boards of said one side of thewall, said plate section being disposed to reside on the side of saidboards opposite said one side; a plurality of spaced apart tabs struckfrom one of said sections so as to be coplanar with said plate sectionand extend from said first bend line in a direction opposite said platesection to define, in cooperation with the inner planar element of theflange, a discontinuous groove for receiving the edge of the other ofsaid boards of said one side of the wall; a second bend line parallelyspaced from sAid first bend line at the end of the plate sectionopposite the first bend line; a second web section extending from saidsecond bend line perpendicular to the plate section, said second websection terminating at an edge disposed at a distance from said platecorresponding to the thickness of the hollow core; and a second flangeextending from last said edge in parallelism with said continuous flangefor affording attachment of the boards that define the second side ofthe wall, the combination of said second flange, said second web andsaid plate section defining a channel section spaced from said one side,said channel section reinforcing said stud against distortion in thepresence of an elevated temperature on said one side.
 2. A studaccording to claim 1 wherein said first web section defines at least oneopening therein for affording visual access to said substantiallycontinuous groove from the side of said first section opposite saidgroove.
 3. A stud according to claim 1 wherein said tabs are struck fromsaid first web section thereby defining a plurality of spaced apartopenings in said first web section to afford visual access to saidsubstantially continuous groove from the side of said first sectionopposite said groove.
 4. A stud according to claim 1 including a lipextending from a portion of said second flange remote from said edge,said lip extending generally normal to said second flange toward saidfirst mentioned flange for reinforcing said second flange, said lipterminating in spaced apart relation to said first mentioned flange. 5.A stud according to claim 1 wherein said tabs include at the marginthereof remote from said second bend line a flared portion that iscurved away from said flange for facilitating entry of the edge of agypsum board into said discontinuous groove.
 6. A stud according toclaim 1 wherein said tabs each include at least one reinforcing ribextending generally normal to said first bend line, said rib beingformed integrally of said tab and including a portion oblique of theplane of said tab.